Automatic purifying device for engine exhaust gases

ABSTRACT

An automatic purifying device for engine exhaust gases is disclosed. Exhaust gases flow through a necked portion to be speeded and the temperature of the exhaust gases is kept uniform after entering an exhaust inlet, and the speeded exhaust gases then pass through a flared mouth so as to be diffused through metal catalyst carriers and a straight-through ceramic filter or wall-flow filter, allowing the poisonous emissions such as nitrogen oxides (NOx) to collide with the metal catalyst carriers to generate high heat to ignite carbon particles, carbon monoxide, hydrocarbons, and the like which are then decomposed and reduced to nitrogen gas and water by added urea or ammonia in the middle of passing through the straight-through ceramic filter or wall-flow filter, where the generated water can then be discharged through a drain port, thereby decreasing pollution to the environment.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a catalytic converter used specially for an engine exhaust pipe, and more particularly to a device capable of purifying engine exhaust gas effectively.

DESCRIPTION OF THE PRIOR ART

General vehicle engine exhaust gases are discharged through an exhaust pipe and then flow immediately to the atmosphere through a muffler after it enters the exhaust pipe and processed by an oxidation catalyst (DOC) device, causing toxic gases such as unpurified exhaust carbon particles (PM), hydrocarbons (HC), carbon monoxide (CO), nitrogen oxide (NO_(x)) and greenhouse gases such as Carbon dioxide (CO₂), nitrogen oxide (NO_(x)) to be discharged directly to the atmosphere, not only polluting the atmosphere to form haze and the first level of carcinogenic air pollution to endanger human health, but forming acidic precipitates such as nitrate, sulfate and carbonate after these poisonous gases are caught in the atmosphere by evaporated water and thus settled to acidify soil to cause a human food crisis, and to acidify ocean to cause the death of marine organisms, the diversion of ocean currents and the acceleration of extreme climate. Therefore, mankind is faced with an unprecedented century catastrophe if there is no improvement in this situation.

Currently, the world's major automobile plants endeavor to do researches and developments unceasingly; methods such as exhaust gas recirculation (EGR), selective catalytic reduction (SCR) and diesel particulate filter (DPF) are becoming the mainstreams of automobile exhaust purification. The provisions of the EU to actively reduce gasoline and diesel emission reduction schedule allows each big automobile manufacturer to follow. It is necessary to enter stage EU6 as early as in 2014, but the world's big car plants still stay at stage EU5 announced in 2011, resulting in the century scandal that Volkswagen Company has no choice but to cheat on the emission test report with software.

Exhaust emissions from diesel vehicles contain not only carbon particles but Nitrogen oxides (NOx) such that selective catalytic reduction (SCR) is conventionally used to process Nitrogen oxides; a SCR system pours urea into burned exhaust gases through a urea cylinder installed in a vehicle to convert the hot exhaust gases to ammonia (NH₃), and ammonia is reduced chemically with nitrogen oxides in the SCR system and converted to nitrogen and water which do not affect the natural environment. But, because the above exhaust emission method is to pass exhaust gases through an exhaust pipe and the SCR system at a uniform rate, unable to keep the temperature of the exhaust gases effectively, causing poisonous exhaust emissions such as carbon particles, carbon monoxide and hydrocarbons not to be burned completely and effectively such that it cannot further reduce pollution to the environment.

SUMMARY OF THE INVENTION

To solve the defects of conventional engine purification processing devices mentioned above, the present invention is proposed.

The present invention proposes an automatic purifying device for engine exhaust gases, characterized in that a necked portion, a flared mouth, a plurality of metal catalyst carries and at least one straight-through ceramic filter or wall-flow filter are configured in sequence inside an exhaust pipe in an axial direction from an exhaust inlet at one end of the exhaust pipe toward an exhaust outlet at the opposed end thereof Exhaust gases flow through the necked portion to be speeded and the temperature of the exhaust gases is kept uniform after entering the exhaust inlet, and the speeded exhaust gases then pass through a flared mouth so as to be diffused through the metal catalyst carriers and the straight-through ceramic filter or wall-flow filter, allowing the poisonous emissions such as nitrogen oxides (NOx) to collide with the metal catalyst carriers to generate high heat to ignite carbon particles, carbon monoxide, hydrocarbons, and the like which are then decomposed and reduced to nitrogen gas and water by added urea or ammonia in the middle of passing through the straight-through ceramic filter or wall-flow filter, thereby decreasing pollution to the environment.

An automatic purifying device for engine exhaust gases according to the present invention includes: an exhaust pipe, comprising an exhaust inlet and exhaust outlet positioned on two axial ends thereof and in communication with each other, a necked portion and flared mouth being configured in sequence between the exhaust inlet and exhaust outlet in an axial direction from the exhaust inlet toward the exhaust outlet, and the necked portion being smaller than the flared mouth in diameter; a plurality of metal catalyst carriers, arranged axially in sequence behind the flared mouth; and at least one straight-through ceramic filter, covered with a ceramic wool and configured between the last arranged metal catalyst carrier and the exhaust outlet.

Preferably, an air intake allowing the inside of the exhaust pipe to be in communication with the outside thereof is configured on the wall of the neck portion, allowing a negative pressure to be generated inside the exhaust pipe while the exhaust gases pass through the necked portion to be speeded, thereby increasing burning efficiency by inhaling air into the exhaust pipe through the air intake.

Optionally, the straight-through ceramic filter inside the exhaust pipe may be replaced with a wall-flow filter.

Preferably, the metal catalyst carriers and straight-through ceramic or wall-flow filter are arranged distantly in the exhaust pipe.

Preferably, a drain port is configured on the wall of the exhaust pipe between one of the metal catalyst carriers and the straight-through ceramic filter, and a bolt adapted to close and open the drain port is configured on the drain port.

Preferably, the metal catalyst carrier is coated with platinum and palladium-based oxidation catalyst.

The advantages of the present invention are in that: after the exhaust pipe of the present invention is installed in a vehicle, exhaust gases, upon vehicle driving, flow through the necked portion to be speeded and the temperature of the exhaust gases is kept uniform after entering the exhaust inlet, a negative pressure is formed inside the exhaust pipe while the exhaust gases are speeded in the necked portion, and thereupon, air outside the exhaust pipe is inhaled into the exhaust pipe through the air intake to mix with the exhaust gases, and the speeded exhaust gases mixed with air then pass through the flared mouth so as to be diffused through the metal catalyst carriers and straight-through ceramic filter or wall-flow filter, allowing the poisonous emissions such as nitrogen oxides (NOx) to collide with the metal catalyst carriers to generate high heat to ignite carbon particles, carbon monoxide, hydrocarbons, and the like which are decomposed and reduced to nitrogen gas and water by the added urea or ammonia in the middle of passing through the straight-through ceramic filter or wall-flow filter, thereby decreasing pollution to the environment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a preferred embodiment of the present invention;

FIG. 2 is a perspective view of the embodiment of the present invention; and

FIG. 3 is a cross-sectional view of another preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, an automatic purifying device for engine exhaust gases according to the present invention, in a preferred embodiment, includes an exhaust pipe 1 which further includes an exhaust inlet 11 and exhaust outlet 12 positioned on the two axial ends thereof and in communication with each other, where a necked portion 13 and flared mouth 14 are configured in sequence between the exhaust inlet 11 and exhaust outlet 12 in an axial direction from the exhaust inlet 11 toward the exhaust outlet 12, and the necked portion 1 is smaller than the flared mouth 12 in diameter. Furthermore, an air intake 10 adapted to communicate the inside of the exhaust pipe 1 with the outside thereof is configured on the wall of the necked portion 13.

Furthermore, a plurality of metal catalyst carriers 2 and at least one straight-through ceramic filter 3, which are arrange distantly in the exhaust pipe 1, are configured axially in sequence behind the flared mouth 14 of the exhaust pipe 1, where the metal catalyst carriers 2 are respectively coated with platinum and palladium-based oxidation catalyst, and the straight-through ceramic filter 2 is covered with a ceramic wool 31 and positioned between the last metal catalyst carrier 2 and exhaust outlet 12. Optionally, the straight-through ceramic filter 3 may also be replaced with a wall-flow filter (not shown in the figures), and the wall-flow filter is covered with the ceramic wool 31, which is used to soak and absorb urea water or ammonia water.

Furthermore, a drain port 15 may further be configured on the wall of the exhaust pipe 1 between one of the metal catalyst carriers 2 and the straight-through ceramic filter 3, and a bolt 16 adapted to close and open the drain port 15 is configured on the drain port 15.

After the exhaust pipe of the present invention is installed in a vehicle, exhaust gases, upon vehicle driving, flow through the necked portion 13 to be speeded and the temperature of the exhaust gases is kept uniform after entering the exhaust inlet 11, a negative pressure is formed inside the exhaust pipe 1 while the exhaust gases are speeded in the necked portion 13, and thereupon, air outside the exhaust pipe 1 is inhaled into the exhaust pipe 1 through the air intake 10 to mix with the exhaust gases, and the speeded exhaust gases mixed with air then pass through the flared mouth 15 so as to be diffused through the metal catalyst carriers 2 and straight-through ceramic filter 3 or wall-flow filter, allowing the poisonous emissions such as nitrogen oxides (NOx) to collide with the metal catalyst carriers 2 to generate high heat to ignite carbon particles, carbon monoxide, hydrocarbons, and the like which are decomposed and reduced to nitrogen gas and water by the added urea or ammonia in the middle of passing through the straight-through ceramic filter 3 or wall-flow filter, where the generated water can then be discharged through the drain port 15, thereby decreasing pollution to the environment.

FIG. 3 shows another preferred embodiment of an automatic purifying device for engine exhaust gases according to the present invention, the present embodiment basically has the same structures as the embodiment mentioned above, except there is no configuration of the air intake 10 on the exhaust pipe 1 in the present embodiment. Similarly, exhaust gases flow through the necked portion 13 to be speeded and the temperature of the exhaust gases is kept uniform after entering the exhaust inlet 11, and the speeded exhaust gases then pass through the flared mouth 15 so as to be diffused through the metal catalyst carriers 2 and straight-through ceramic filter 3 or wall-flow filter, allowing the poisonous emissions such as nitrogen oxides (NOx) to collide with the metal catalyst carriers 2 to generate high heat to ignite carbon particles, carbon monoxide, hydrocarbons, and the like which are then decomposed and reduced to nitrogen gas and water by the added urea or ammonia in the middle of passing through the straight-through ceramic filter 3 or wall-flow filter, where the generated water can then be discharged through the drain port 15, thereby decreasing pollution to the environment. 

I claim:
 1. An automatic purifying device for engine exhaust gases, comprising: an exhaust pipe, comprising an exhaust inlet and exhaust outlet positioned on two axial ends thereof and in communication with each other, a necked portion and flared mouth being configured in sequence between said exhaust inlet and exhaust outlet in an axial direction from said exhaust inlet toward said exhaust outlet, and said necked portion being smaller than said flared mouth in diameter; a plurality of metal catalyst carriers, arranged axially in sequence behind said flared mouth; and at least one straight-through ceramic filter, covered with ceramic wool and configured between said last arranged metal catalyst carrier and said exhaust outlet.
 2. The device according to claim 1, wherein an air intake allowing an inside of said exhaust pipe to be in communication with an outside thereof is configured on a wall of said neck portion.
 3. The device according to claim 1, wherein a drain port is configured on a wall of said exhaust pipe between one of said metal catalyst carriers and said straight-through ceramic filter, and a bolt adapted to close and open said drain port is configured on said drain port. 